Ah yes solving the problem that the industry created rather than never having it in the first place. M.2 is the dumbest desktop/workstation interface choice and it's here to stay because it's cheaper to design boards this way.
While you could probably use this in most machines you're still sandwiching heat between heat especially if you're using an air cooler on your CPU. A much better solution would be for the M.2 slots to be away from the CPU and GPU, but that would cost board manufacturers money.
I would be thrilled if they just nuked M.2 entirely and shifted the consumer industry to E1.S (personally I'd be happy with 4x SlimSAS plugs, but I get that people don't like wires). This would cost more money and likely require the industry to agree on a small backplane design though so never going to happen.